Question

50 mL of hydrogen diffuses out through a small hole of a vessel, in 20 minutes. The time taken by 40 mL of oxygen to diffuse out is

• A. 32 minutes
• B. 64 minutes
• C. 8 minutes
• D. 12 minutes

Answer 1

Answer: (B)

64 minutes

Answer 2

Rate $\left( H _{2}\right)=\frac{50}{20}=2.5$
Rate $\left( O _{2}\right)=\frac{40}{t}$
$\frac{ r _{ H _{2}}}{ r _{ O }}=\frac{2.5}{40 / t }=\sqrt{\left( M _{ O_2} / M _{ H _2}\right)}=\sqrt{(32 / 2)}=4$
$\Rightarrow 2.5\, t =160$
$t =64\, \min$